Acute Disseminated Encephalomyelitis (ADEM)
Lesson Objectives
By the end of this lesson, learners should be able to:
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Define ADEM and describe its pathophysiology.
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Identify typical triggers, including post-vaccination and viral illness.
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Recognize the clinical signs and symptoms of ADEM in children.
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Understand the diagnostic criteria, including cerebrospinal fluid (CSF) and MRI findings.
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Outline the supportive and pharmacological management of ADEM.
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Identify referral criteria for specialized care.
Description
ADEM is a demyelinating disorder of the white matter of the brain and spinal cord. It may follow vaccination or a systemic viral illness and is characterized by acute onset of encephalopathy with focal or multifocal neurological deficits. Symptoms typically peak between 2–5 days from onset but may evolve over up to 3 months. CSF usually shows pleocytosis with normal protein and glucose levels.
Clinical Features
| Feature | Description |
|---|---|
| Encephalopathy | Altered consciousness or behaviour not explained by fever, systemic illness, or postictal state |
| Multifocal CNS symptoms | May include hemiparesis, pyramidal signs, ataxia, cranial nerve palsies |
| Seizures | Can occur during acute phase |
| Meningism | Neck stiffness, photophobia, or other meningeal signs |
| Optic neuritis | Visual disturbances due to inflammation of optic nerve |
| MRI findings | Brain MRI shows lesions consistent with demyelination in the acute (first 3 months) phase |
Investigations
| Investigation | Finding |
|---|---|
| Cerebrospinal fluid | Pleocytosis, normal protein and glucose |
| MRI brain | Demyelinating lesions consistent with ADEM |
MRI is required for definitive diagnosis and helps distinguish ADEM from other demyelinating conditions.
Management
| Aspect | Action |
|---|---|
| Supportive care | Preferably in ICU; maintain airway and ventilation; mechanical ventilation may be necessary |
| Pharmacological | Immune modulators and intravenous immunoglobulins under neurologist supervision |
| Monitoring | Frequent neurological assessment, supportive care for vitals, hydration, and nutrition |
Referral Criteria
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Any child suspected of ADEM should be referred for specialist care.
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MRI confirmation is required for diagnosis.
Key Summary
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ADEM is an acute demyelinating disorder of white matter following vaccination or viral illness.
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Presents with encephalopathy and multifocal neurological deficits, often with seizures.
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CSF shows pleocytosis with normal protein and glucose.
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MRI is essential for diagnosis.
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Management is supportive and immunomodulatory, preferably in ICU.
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Prompt referral to neurology is recommended.